JP7692006B2 - Active Pen - Google Patents

Description

The present invention relates to an active pen, and more particularly to an active pen incorporating a haptic element for providing sensory feedback to a user.

There is a known technology that reproduces the feel of writing on paper by controlling a haptic element built into an electronic pen from an electronic device such as a tablet terminal. Examples of this type of technology are disclosed in Patent Documents 1 to 3.

JP 2019-066960 A JP 2009-238081 A JP 2002-259044 A

However, when the haptic element in an electronic pen is controlled from an electronic device, there is a slight time lag in the control, which can cause the vibration of the haptic element to not stop immediately even after the pen tip leaves the panel surface, making the user feel uncomfortable.

Therefore, one object of the present invention is to provide an active pen that can quickly stop vibration of the haptic element after the pen tip is separated from the panel surface.

An active pen according to a first aspect of the present invention includes a haptic element, a pressure sensor that detects pressure applied to the pen tip, a pen tip electrode provided at the pen tip, a communication unit that performs short-range wireless communication, and a signal processing unit that transmits a downlink signal from the pen tip electrode including a pen pressure value indicating the magnitude of pressure detected by the pressure sensor, wherein the signal processing unit starts vibration of the haptic element when it receives a control signal from the communication unit instructing the haptic element to start vibrating, and stops vibration of the haptic element when the pen pressure value falls below a first predetermined value.

An active pen according to a second aspect of the present invention includes a haptic element, a pressure sensor that detects pressure applied to the pen tip, and a signal processing unit that starts vibration of the haptic element in response to pen down and stops vibration of the haptic element in response to pen up, wherein the signal processing unit stops vibration of the haptic element in response to a writing pressure value indicating the magnitude of pressure detected by the pressure sensor falling below a first predetermined value.

According to the present invention, the vibration of the haptic element can be stopped in the active pen according to the pen pressure value, so that the vibration of the haptic element can be stopped quickly after the pen tip is released from the panel surface.

1 is a diagram showing a configuration of a position detection system 1 according to an embodiment of the present invention. FIG. 2 is a diagram showing a sequence of processes executed in the position detection system 1 according to the embodiment of the present invention. FIG. 11 is a diagram showing a sequence of processes executed in a position detection system 1 according to a modified example of the present embodiment.

Below, a preferred embodiment of the present invention is described in detail with reference to the attached drawings.

Figure 1 is a diagram showing the configuration of a position detection system 1 according to an embodiment of the present invention. As shown in the figure, the position detection system 1 is configured with an active pen 2 and an electronic device 3 that is a position detection device that detects the active pen 2.

The electronic device 3 is a computer having a panel surface 3a, such as a tablet computer or a digitizer. The electronic device 3 includes a sensor 30 arranged on the panel surface 3a, a sensor controller 31 connected to the sensor 30, a display 32 arranged superimposed on the sensor 30, a wireless communication unit 33, and a host processor 34 that controls each part of the electronic device 3 including these.

The host processor 34 is the central processing unit of the electronic device 3, and is configured to read and execute various programs from a memory (not shown). The programs executed in this manner include the operating system of the electronic device 3 and various applications including a drawing application. Of these, the drawing application is a program for executing a process of generating digital ink based on the position and data supplied from the sensor controller 31 and storing it in a memory within the electronic device 3, and a process of rendering the generated digital ink, generating a video signal showing the result, and supplying it to the display 32. The display 32 is a device that displays the video signal supplied from the host processor 34, and is configured, for example, by a liquid crystal display or an organic EL display.

The sensor 30 is a device having a structure in which multiple sensor electrodes are arranged within the panel surface 3a. Some of the multiple sensor electrodes constituting the sensor 30 can be used as a common electrode of the display 32 (an electrode for supplying a ground potential commonly to each pixel). When this sharing is performed, the electronic device 3 constitutes a so-called "in-cell type" position detection device. On the other hand, when this sharing is not performed, the electronic device 3 constitutes a so-called "on-cell type" or "out-cell type" position detection device. The present invention can be suitably applied to any of the electronic devices 3.

The sensor controller 31 is an integrated circuit having a function of detecting the position of the active pen 2 on the panel surface 3a. In this embodiment, an example in which this detection is performed by an active electrostatic method (AES) is described, but the present invention can also be suitably applied to cases in which the position of the active pen 2 is detected by other methods such as an electromagnetic induction method (EMR).

The sensor controller 31, which supports the active electrostatic method, is configured to communicate bidirectionally with the active pen 2 through electrostatic coupling between the sensor 30 and an electrode (pen tip electrode 21, described below) in the active pen 2. Hereinafter, the signal transmitted from the sensor controller 31 to the active pen 2 by this communication will be referred to as the "uplink signal US," and the signal transmitted from the active pen 2 to the sensor controller 31 will be referred to as the "downlink signal DS."

The uplink signal US is a signal periodically transmitted by the sensor controller 31. The uplink signal US notifies the active pen 2 of the transmission timing of the downlink signal DS and the reception timing of the next uplink signal US, and also plays a role in transmitting commands to the active pen 2. On the other hand, the downlink signal DS is a signal including a position signal, which is an unmodulated carrier signal, and a data signal, which is a carrier signal modulated by data. The position signal is a signal for causing the sensor controller 31 to detect the position of the active pen 2, and the sensor controller 31 is configured to derive the position of the active pen 2 on the panel surface 3a based on the distribution of the reception strength of the position signal at each sensor electrode in the sensor 30. The data transmitted by the data signal includes switch information and writing pressure values, which will be described later, as well as data instructed to be transmitted by a command. The sensor controller 31 acquires the data transmitted by the active pen 2 by demodulating the data signal. The position derived by the sensor controller 31 and the acquired data are sequentially supplied from the sensor controller 31 to the host processor 34.

The wireless communication unit 33 is a communication device for performing short-range wireless communication such as Bluetooth (registered trademark), and is connected to the host processor 34. The host processor 34 performs short-range wireless communication with the active pen 2 and other devices (keyboard, mouse, speaker, headphones, etc.) via the wireless communication unit 33.

The signal that the host processor 34 transmits to the active pen 2 through the wireless communication unit 33 includes a control signal for the haptic element 26, which will be described later. The host processor 34 is configured to detect pen-down when the writing pressure value supplied from the sensor controller 31 exceeds a predetermined value V2 (typically, V2=0) and transmit a control signal instructing the haptic element 26 to start vibrating, and to detect pen-up when the writing pressure value supplied from the sensor controller 31 reaches the predetermined value V2 and transmit a control signal instructing the haptic element 26 to stop vibrating. This point will be described in more detail later with reference to FIG. 2.

The active pen 2 is an electronic pen (stylus) that supports the active electrostatic method, and as shown in FIG. 1, is composed of a core body 20, a pen tip electrode 21, a side switch 22, a pressure sensor 23, a battery 24, a wireless communication unit 25, a haptic element 26, and an integrated circuit 27. The core body 20 is a member that constitutes the pen shaft of the active pen 2. The tip of the core body 20 constitutes the pen tip of the active pen 2, and the end abuts the pressure sensor 23. The pen tip electrode 21 is a conductor disposed at the pen tip, and is electrically connected to the integrated circuit 27. Note that multiple pen tip electrodes 21 may be provided within the active pen 2, and different pen tip electrodes 21 may be used for transmission and reception, for example.

The side switch 22 is a push button switch provided on the surface of the active pen 2, and is configured to be turned on and off by the user. The operation state (on/off state) of the side switch 22 is supplied to the integrated circuit 27 as, for example, 2-bit switch information. The pressure sensor 23 is a sensor that detects the pressure applied to the tip (pen tip) of the core body 20. The pressure detected by the pressure sensor 23 is supplied to the integrated circuit 27 as, for example, a 12-bit pen pressure value. The battery 24 serves to supply the power necessary for the integrated circuit 27 to operate.

The wireless communication unit 25 is a communication device for performing short-range wireless communication such as Bluetooth (registered trademark). The integrated circuit 27 performs short-range wireless communication with the host processor 34 of the electronic device 3 via the wireless communication unit 25. The signal that the integrated circuit 27 receives from the host processor 34 through this short-range wireless communication includes a control signal for the haptic element 26 described above.

The haptic element 26 is a device for providing sensory feedback to the user of the active pen 2, and is composed of, for example, a vibrator of the eccentric rotating mass type, the linear resonant actuator type, or the piezoelectric actuator type. The haptic element 26 may be composed of a magnetic fluid whose hardness can be controlled by the frequency of the applied pulse current. In the following, the explanation will be continued on the assumption that the haptic element 26 is composed of a vibrator of the eccentric rotating mass type. In this case, the haptic element 26 is composed of a motor and an eccentric weight attached to the rotation shaft of the motor.

The integrated circuit 27 is a circuit that executes various processes for communicating with the sensor controller 31 through the pen tip electrode 21 and with the host processor 34 through the wireless communication unit 25. Specifically, the integrated circuit 27 performs the following processes: receiving an uplink signal US by detecting a change in the potential of the pen tip electrode 21; determining a transmission/reception schedule for the downlink signal DS and the next uplink signal US using the reception timing of the uplink signal US as a reference time; generating a downlink signal DS in response to a command included in the uplink signal US; and transmitting the generated downlink signal DS by changing the potential of the pen tip electrode 21 according to the determined transmission/reception schedule. The integrated circuit 27 also performs pairing with the host processor 34 through the wireless communication unit 25, receives various control signals from the paired host processor 34, and performs processing based on the received control signals.

The processing based on the received control signal includes processing to start or stop the vibration of the haptic element 26. Specifically, the integrated circuit 27 is configured to start or stop the vibration of the haptic element 26 in response to the control signal transmitted by the host processor 34. However, the integrated circuit 27 also performs processing to stop the vibration of the haptic element 26 when the writing pressure value supplied from the pressure sensor 23 becomes equal to or less than the predetermined value V1. The predetermined value V1 is a value (V1>V2) greater than the above-mentioned predetermined value V2 (a value used by the host processor 34 to detect pen-down and pen-up). In actual processing, the integrated circuit 27 stops the vibration of the haptic element 26 at the earlier of the timing of reception by the wireless communication unit 25 of a control signal instructing the haptic element 26 to stop vibrating, or the timing when the writing pressure value supplied from the pressure sensor 23 falls below the predetermined value V1.

Figure 2 is a diagram showing the sequence of processing executed in the position detection system 1. This figure shows only the processing related to the control of the haptic element 26. Below, with reference to Figure 2, the processing performed by the active pen 2, the sensor controller 31, and the host processor 34 in relation to the control of the haptic element 26 will be explained.

2, when the active pen 2 first transmits a downlink signal DS (step S1), the sensor controller 31 derives coordinates indicating the position of the active pen 2 on the panel surface 3a based on the position signal in the downlink signal DS, and obtains data such as the pen pressure value from the data signal in the downlink signal DS and supplies the data to the host processor 34 (step S2). The processes of steps S1 and S2 are executed each time the active pen 2 transmits a downlink signal DS.

Next, each time the pen pressure value is supplied from the sensor controller 31, the host processor 34 determines whether or not a pen-down or pen-up has occurred based on the series of pen pressure values supplied up to that point (steps S3 and S4), and transmits a control signal for the haptic element 26 using short-range wireless communication according to the result (steps S5 and S6). Specifically, the host processor 34 detects the occurrence of a pen-down when the pen pressure value changes from a value equal to or less than a predetermined value V2 (typically, V2=0) to a value greater than the predetermined value V2 (step S3), and transmits a control signal instructing the haptic element 26 to start vibrating (step S5). In addition, the host processor 34 detects the occurrence of a pen-up when the pen pressure value changes from a value greater than the predetermined value V2 to a value equal to or less than the predetermined value V2 (step S4), and transmits a control signal instructing the haptic element 26 to stop vibrating (step S6).

The integrated circuit 27 of the active pen 2, which has received the control signal instructing the haptic element 26 to start vibrating, starts the vibration of the haptic element 26 (step S7). Specifically, the vibration of the haptic element 26 is started by applying a current in a first direction to the motor that constitutes the haptic element 26. This allows the user to feel a vibration when sliding the active pen 2 on the panel surface 3a, similar to the vibration felt when sliding a real writing implement such as a ballpoint pen on paper.

While vibrating the haptic element 26, the integrated circuit 27 performs a process of comparing the pen pressure value supplied from the pressure sensor 23 with a predetermined value V1 each time the pen pressure value is supplied (step S8). If the integrated circuit 27 detects that the pen pressure value is equal to or lower than the predetermined value V1 as a result of the comparison, it stops the vibration of the haptic element 26 (step S9). The integrated circuit 27 also stops the vibration of the haptic element 26 when it receives a control signal instructing the haptic element 26 to stop vibrating (step S10). Only step S9 or step S10, whichever is executed first, will actually be executed.

Here, when stopping the vibration of the haptic element 26 in step S9 or step S10, it is preferable that the integrated circuit 27 stops the vibration of the haptic element 26 by applying a current to the motor in a direction opposite to the first direction described above, and then stopping the application of the current to the motor. In this way, it is possible to quickly stop the residual vibration of the haptic element 26 due to inertia, compared to a case in which the application of the current to the motor is stopped without applying a current to the motor in a direction opposite to the first direction.

As described above, according to the position detection system 1 of this embodiment, it is possible to stop the vibration of the haptic element 26 in the active pen 2 according to the pen pressure value. Therefore, it is possible to quickly stop the vibration of the haptic element 26 after the pen tip is released from the panel surface 3a.

Furthermore, according to the active pen 2 of this embodiment, the vibration of the haptic element 26 is stopped when the writing pressure value falls below a predetermined value V1 that is greater than a predetermined value V2 that is generally used to determine pen down and pen up. Therefore, even if there is residual vibration of the haptic element 26 due to inertia, it is possible to immediately stop the vibration of the haptic element 26 after the pen tip leaves the panel surface 3a.

However, the present invention can also be suitably applied when the predetermined value V1 is equal to the predetermined value V2. In this case, after the pen tip is released from the panel surface 3a, residual vibration of the haptic element 26 due to inertia may remain, but the vibration of the haptic element 26 can be stopped more quickly than when it is controlled by the electronic device 3.

Furthermore, according to the active pen 2 of this embodiment, when the vibration of the haptic element 26 is stopped, a current is applied to the motor in the opposite direction to that applied previously, so that the residual vibration of the haptic element 26 caused by inertia can be quickly stopped.

Although the above describes preferred embodiments of the present invention, the present invention is in no way limited to these embodiments, and it goes without saying that the present invention can be embodied in various forms without departing from the spirit of the present invention.

Figure 3 is a diagram showing a sequence of processing executed in a position detection system 1 according to a modified example of this embodiment. This modified example differs from this embodiment in that processing of steps S10 to S13 is executed instead of steps S3 to S6 shown in Figure 2.

To explain in more detail, in this modified example, the sensor controller 31 determines whether or not a pen-down or pen-up has occurred based on the series of pen pressure values acquired up to that point (steps S10 and S11), and transmits a control signal for the haptic element 26 using the uplink signal US according to the result (steps S12 and S13). The specific processing of steps S10 to S13 is the same as steps S3 to S6, except that the uplink signal US is used instead of short-range wireless communication.

Even when the sensor controller 31 uses the uplink signal US to transmit a control signal for the haptic element 26 in this way, the present invention makes it possible to stop the vibration of the haptic element 26 in the active pen 2 according to the pen pressure value. Therefore, it becomes possible to stop the vibration of the haptic element 26 quickly after the pen tip is released from the panel surface 3a.

REFERENCE SIGNS LIST 1 Position detection system 2 Active pen 3 Electronic device 3a Panel surface 20 Core body 21 Pen tip electrode 22 Side switch 23 Pressure sensor 24 Battery 25 Wireless communication unit 26 Haptic element 27 Integrated circuit 30 Sensor 31 Sensor controller 32 Display 33 Wireless communication unit 34 Host processor DS Downlink signal US Uplink signal

Claims (8)

A haptic element;
A pressure sensor that detects the pressure applied to the pen tip;
A pen tip electrode provided at the pen tip;
A communication unit that performs short-range wireless communication;
an integrated circuit that transmits, from the pen tip electrode, a downlink signal including a writing pressure value indicating the magnitude of pressure detected by the pressure sensor;
The integrated circuit comprises:
When a control signal instructing the haptic element to start vibrating is received from the communication unit, the haptic element starts vibrating.
When the writing pressure value falls below a first predetermined value that is greater than a second predetermined value used as a criterion for detecting pen-down , the vibration of the haptic element is stopped.
Active pen. The control signal is a signal generated by a host processor connected to a sensor controller that receives the downlink signal through capacitive coupling between a sensor disposed in a panel surface and the pen tip electrode;
When the writing pressure value supplied from the sensor controller exceeds the second predetermined value, the host processor transmits a control signal via the short-range wireless communication to instruct the haptic element to start vibrating.
The active pen of claim 1 . A haptic element including a motor;
A pressure sensor that detects the pressure applied to the pen tip;
A pen tip electrode provided at the pen tip;
A communication unit that performs short-range wireless communication;
an integrated circuit that transmits, from the pen tip electrode, a downlink signal including a writing pressure value indicating the magnitude of pressure detected by the pressure sensor;
The integrated circuit comprises:
When a control signal instructing the haptic element to start vibrating is received from the communication unit, a current in a first direction is applied to the motor to start vibrating the haptic element,
when the writing pressure value falls below a first predetermined value, a current is applied to the motor in a direction opposite to the first direction, and then the application of the current to the motor is stopped, thereby stopping the vibration of the haptic element ;
Active pen. The control signal is a signal generated by a host processor connected to a sensor controller that receives the downlink signal through capacitive coupling between a sensor disposed in a panel surface and the pen tip electrode;
When the writing pressure value supplied from the sensor controller exceeds a second predetermined value, the host processor transmits a control signal via the short-range wireless communication to instruct the haptic element to start vibrating.
The active pen according to claim 3 . the first predetermined value is greater than the second predetermined value;
The active pen according to claim 4 . When the writing pressure value supplied from the sensor controller falls below the second predetermined value, the host processor transmits a control signal via the short-range wireless communication to instruct the haptic element to stop vibrating.
6. An active pen according to claim 2, 4 or 5 . A haptic element;
A pressure sensor that detects the pressure applied to the pen tip;
an integrated circuit that starts vibration of the haptic element in response to a pen-down and stops vibration of the haptic element in response to a writing pressure value indicating a magnitude of pressure detected by the pressure sensor falling below a first predetermined value that is greater than a second predetermined value used as a criterion for detecting the pen-down ;
Includes an active pen. A pen tip electrode provided at the pen tip;
A communication unit that performs short-range wireless communication,
The integrated circuit comprises:
transmitting a downlink signal including a writing pressure value indicating the magnitude of the pressure detected by the pressure sensor from the pen tip electrode;
When a control signal instructing the haptic element to start vibrating is received from the communication unit, the haptic element starts vibrating;
The control signal is a signal generated by a host processor connected to a sensor controller that receives the downlink signal through capacitive coupling between a sensor disposed in a panel surface and the pen tip electrode;
The host processor:
detecting the pen-down when the writing pressure value supplied from the sensor controller exceeds the second predetermined value;
When the pen-down is detected, a control signal instructing the haptic element to start vibrating is transmitted via the short-range wireless communication, thereby causing the haptic element to start vibrating.
The active pen of claim 7 .

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